Air conditioning system

Abstract

The invention provides an air-conditioning system which comprises at least two air-conditioning outdoor units and at least two air-conditioning indoor units, each air-conditioning outdoor unit is connected with the air-conditioning indoor unit, the air-conditioning system further comprises defrosting equipment which comprises a regulation and control device and a defrosting device, and the defrosting device is connected with each air-conditioning outdoor unit through the regulation and control device. And all the air conditioner outdoor units are subjected to defrosting operation. According to the air conditioning system, the problem that in the prior art, the manufacturing cost of an air conditioning system is high is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of air conditioning equipment, and in particular, to an air conditioning system. Background Art

[0002] At present, in order to defrost the outdoor units of an air conditioning system with multiple outdoor units, multiple defrost control devices are usually provided, that is, one defrost control device is equipped for each outdoor unit of the air conditioning system, so that a part of the outdoor units of the air conditioning system can perform self-circulation defrosting without absorbing heat from the indoor side. At the same time, during the defrosting process of some outdoor units of the air conditioning system, another part of the outdoor units of the air conditioning system can operate for heating to provide high-temperature refrigerant for the indoor unit, realizing continuous heating on the indoor side, and continuous heating of the indoor unit during the defrosting process can be achieved, reducing the influence of the defrosting process of the outdoor units of the air conditioner on the indoor thermal comfort.

[0003] However, the above scheme requires each outdoor unit of the air conditioner to be equipped with a corresponding defrost control device one by one. In practical engineering applications, it has high requirements for the installation space and the manufacturing cost of the product is relatively high. Summary of the Invention

[0004] The main object of the present invention is to provide an air conditioning system to solve the problem of relatively high manufacturing cost of the existing air conditioning system.

[0005] To achieve the above object, the present invention provides an air conditioning system, including at least two outdoor units of the air conditioner and an indoor unit of the air conditioner. Each outdoor unit of the air conditioner is connected to the indoor unit of the air conditioner. The air conditioning system further includes: a defrosting device, including a control device and a defrosting device. The defrosting device is connected to each outdoor unit of the air conditioner through the control device to perform defrosting operations on each outdoor unit of the air conditioner.

[0006] Further, the defrosting device is an evaporation component, and the evaporation component includes a first heat exchange channel and a second heat exchange channel for heat exchange; at least two air conditioner outdoor units include N first air conditioner outdoor units and M second air conditioner outdoor units; where 1 ≤ N < the total number of air conditioner outdoor units; 1 ≤ M < the total number of air conditioner outdoor units; the control device is used to control the on-off of the first air conditioner outdoor unit and the air conditioner indoor unit, the on-off of the second air conditioner outdoor unit and the air conditioner indoor unit, the on-off of the first air conditioner outdoor unit and the first heat exchange channel, and the on-off of the second air conditioner outdoor unit and the second heat exchange channel; the air conditioning system has a defrosting state. When the air conditioning system is in the defrosting state, the first air conditioner outdoor unit is in the defrosting mode, the first air conditioner outdoor unit is disconnected from the air conditioner indoor unit and connected to the first heat exchange channel; the second air conditioner outdoor unit is in the heating mode, and the second air conditioner outdoor unit is connected to both the air conditioner indoor unit and the second heat exchange channel; or, the first air conditioner outdoor unit is in the heating mode, the first air conditioner outdoor unit is connected to both the air conditioner indoor unit and the first heat exchange channel; the second air conditioner outdoor unit is in the defrosting mode, and the second air conditioner outdoor unit is disconnected from the air conditioner indoor unit and connected to the second heat exchange channel.

[0007] Further, the air conditioner outdoor unit includes a connecting pipeline, and the air conditioner outdoor unit is connected to the air conditioner indoor unit through the connecting pipeline; the control device includes: a defrosting pipeline, including a first defrosting pipeline and a second defrosting pipeline, both the first defrosting pipeline and the second defrosting pipeline are provided in a switchable manner, the first heat exchange channel is connected to the connecting pipeline of the first air conditioner outdoor unit through the first defrosting pipeline, and the second heat exchange channel is connected to the connecting pipeline of the second air conditioner outdoor unit through the second defrosting pipeline; a control valve group, and a control valve group is provided on each connecting pipeline to control the on-off of the connecting pipeline; the control valve group is located on the side close to the air conditioner indoor unit at the connection point of the defrosting pipeline and the connecting pipeline.

[0008] Further, the connecting pipeline includes: a first gas pipe, and the first gas pipes of at least two air conditioner outdoor units are all connected to the second gas pipe of the air conditioner indoor unit; a first liquid pipe, and the first liquid pipes of at least two air conditioner outdoor units are all connected to the second liquid pipe of the air conditioner indoor unit; the first defrosting pipeline includes a first connecting pipe assembly and a second connecting pipe assembly, and the first port of the first heat exchange channel is connected to the first liquid pipes of each first air conditioner outdoor unit through the first connecting pipe assembly; the second port of the first heat exchange channel is connected to the first gas pipes of each first air conditioner outdoor unit through the second connecting pipe assembly; the first connecting pipe assembly is provided in a switchable manner.

[0009] Further, the control device further includes: a first electronic expansion valve, which is arranged on the first connecting pipe assembly to control the on-off of the first connecting pipe assembly.

[0010] Further, the second defrosting pipeline includes a third connecting pipe assembly and a fourth connecting pipe assembly. The third port of the second heat exchange channel is connected to the first gas pipes of each second outdoor air conditioner through the third connecting pipe assembly; the fourth port of the second heat exchange channel is connected to the first liquid pipes of each second outdoor air conditioner through the fourth connecting pipe assembly; the fourth connecting pipe assembly is provided in a switchable manner.

[0011] Further, the control device further includes: a second electronic expansion valve, which is arranged on the fourth connecting pipe assembly to control the on-off of the fourth connecting pipe assembly.

[0012] Further, the connecting pipeline includes: a first gas pipe, and the first gas pipes of at least two outdoor air conditioners are all connected to the second gas pipe of the indoor air conditioner; a first liquid pipe, and the first liquid pipes of at least two outdoor air conditioners are all connected to the second liquid pipe of the indoor air conditioner; the control valve group includes a first valve and a second valve. The first valve is arranged on the first gas pipe and is located on the side close to the indoor air conditioner at the connection point between the defrosting pipeline and the connecting pipeline. The second valve is arranged on the first liquid pipe and is located on the side close to the indoor air conditioner at the connection point between the defrosting pipeline and the connecting pipeline.

[0013] Further, the air conditioning system includes a main gas pipe and a main liquid pipe. The connecting pipeline includes: a first gas pipe, and the first gas pipes of at least two outdoor air conditioners are all connected to the second gas pipe of the indoor air conditioner through the main gas pipe; a first liquid pipe, and the first liquid pipes of at least two outdoor air conditioners are all connected to the second liquid pipe of the indoor air conditioner through the main liquid pipe.

[0014] Further, the number of outdoor air conditioners is 2 or 3 or 4; when the number of outdoor air conditioners is 2, N = 1, M = 1; when the number of outdoor air conditioners is 3, N = 1, M = 2; or, N = 2, M = 1; when the number of outdoor air conditioners is 4, N = 1, M = 3; or, N = 2, M = 2; or, N = 3, M = 1.

[0015] Applying the technical solution of the present invention, the air conditioning system includes at least two outdoor air conditioners and an indoor air conditioner. Each outdoor air conditioner is connected to the indoor air conditioner. The air conditioning system further includes a defrosting device, and the defrosting device includes a control device and a defrosting device. The defrosting device is connected to each outdoor air conditioner through the control device to defrost each outdoor air conditioner. It can be seen that the air conditioning system can realize the defrosting operation of multiple outdoor air conditioners only by setting the defrosting device, reducing the product manufacturing cost and being convenient for installation, and solving the problem of high manufacturing cost of the air conditioning system. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The specification drawings forming a part of this application are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention. In the drawings:

[0017] Figure 1 Shows a schematic diagram of defrosting of the first air-conditioning outdoor unit and heating of the second air-conditioning outdoor unit according to the first embodiment of the air-conditioning system of the present invention;

[0018] Figure 2 Shows a schematic diagram of heating of the first air-conditioning outdoor unit and defrosting of the second air-conditioning outdoor unit according to the first embodiment of the air-conditioning system of the present invention;

[0019] Figure 3 Shows a schematic diagram of refrigeration according to the first embodiment of the air-conditioning system of the present invention;

[0020] Figure 4 Shows a schematic diagram of heating according to the first embodiment of the air-conditioning system of the present invention;

[0021] Figure 5 Shows a schematic diagram of refrigeration according to the second embodiment of the air-conditioning system of the present invention;

[0022] Figure 6 Shows a schematic diagram of heating according to the second embodiment of the air-conditioning system of the present invention;

[0023] Figure 7 Shows a schematic diagram of defrosting of the first air-conditioning outdoor unit and heating of the second air-conditioning outdoor unit according to the second embodiment of the air-conditioning system of the present invention;

[0024] Figure 8 Shows a schematic diagram of heating of the first air-conditioning outdoor unit and defrosting of the second air-conditioning outdoor unit according to the second embodiment of the air-conditioning system of the present invention;

[0025] Figure 9 Shows a schematic diagram of refrigeration according to the third embodiment of the air-conditioning system of the present invention;

[0026] Figure 10 Shows a schematic diagram of heating according to the third embodiment of the air-conditioning system of the present invention;

[0027] Figure 11 Shows a schematic diagram of defrosting of the first air-conditioning outdoor unit and heating of the second air-conditioning outdoor unit according to the third embodiment of the air-conditioning system of the present invention;

[0028] Figure 12 Shows a schematic diagram of heating of the first air-conditioning outdoor unit and defrosting of the second air-conditioning outdoor unit according to the third embodiment of the air-conditioning system of the present invention;

[0029] Figure 13 Shows a schematic diagram of refrigeration according to the fourth embodiment of the air-conditioning system of the present invention;

[0030] Figure 14 Schematic diagram showing heating of the fourth embodiment of the air conditioning system according to the present invention;

[0031] Figure 15 Schematic diagram showing defrosting of the first outdoor air conditioner and heating of the second outdoor air conditioner of the fourth embodiment of the air conditioning system according to the present invention;

[0032] Figure 16 Schematic diagram showing heating of the first outdoor air conditioner and defrosting of the second outdoor air conditioner of the fourth embodiment of the air conditioning system according to the present invention;

[0033] Figure 17 Schematic diagram showing that the first heat exchange channel and the second heat exchange channel of the first embodiment of the air conditioning system according to the present invention adopt a parallel flow.

[0034] Among them, the above-mentioned drawings include the following reference numerals:

[0035] 1, outdoor air conditioner; 11, first outdoor air conditioner; 12, second outdoor air conditioner; 111, first gas pipe; 112, first liquid pipe;

[0036] 2, defrosting device; 201, defrosting device; 202, first electronic expansion valve; 203, second electronic expansion valve; 204, first port; 205, second port; 206, third port; 207, fourth port;

[0037] 21, first connecting pipe assembly; 22, second connecting pipe assembly; 23, third connecting pipe assembly; 24, fourth connecting pipe assembly;

[0038] 211, first valve; 212, second valve;

[0039] 3, indoor air conditioner; 301, second gas pipe; 302, second liquid pipe;

[0040] 401, main gas pipe; 402, main liquid pipe. Detailed implementation manners

[0041] It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the drawings and in combination with the embodiments.

[0042] It should be pointed out that the following detailed description is exemplary and is intended to provide further description of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present application belongs.

[0043] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0044] The present invention provides an air conditioning system. Please refer to Figures 1 to 17 , which includes at least two air conditioner outdoor units 1 and an air conditioner indoor unit 3. Each air conditioner outdoor unit 1 is connected to the air conditioner indoor unit 3. The air conditioning system further includes: a defrosting device 2, which includes a regulating device and a defrosting device 201. The defrosting device 201 is connected to each air conditioner outdoor unit 1 through the regulating device to defrost each air conditioner outdoor unit 1.

[0045] The air conditioning system of the present invention includes at least two air conditioner outdoor units 1 and an air conditioner indoor unit 3. Each air conditioner outdoor unit 1 is connected to the air conditioner indoor unit 3. The air conditioning system further includes a defrosting device 2. The defrosting device 2 includes a regulating device and a defrosting device 201. The defrosting device 201 is connected to each air conditioner outdoor unit 1 through the regulating device to defrost each air conditioner outdoor unit 1. It can be seen that the air conditioning system can realize the defrosting operation of multiple air conditioner outdoor units 1 only by setting the defrosting device 2, reducing the product manufacturing cost and facilitating installation, and solving the problem of relatively high manufacturing cost of the air conditioning system.

[0046] In this embodiment, the defrosting device 201 is an evaporation component. The evaporation component includes a first heat exchange channel and a second heat exchange channel for heat exchange; at least two air conditioner outdoor units 1 include N first air conditioner outdoor units 11 and M second air conditioner outdoor units 12; where 1 ≤ N < the total number of air conditioner outdoor units 1; 1 ≤ M < the total number of air conditioner outdoor units 1; the regulating device is used to regulate the on-off between the first air conditioner outdoor unit 11 and the air conditioner indoor unit 3, the on-off between the second air conditioner outdoor unit 12 and the air conditioner indoor unit 3, and the on-off between the first air conditioner outdoor unit 11 and the first heat exchange channel, and the on-off between the second air conditioner outdoor unit 12 and the second heat exchange channel; the air conditioning system has a defrosting state. When the air conditioning system is in the defrosting state, the first air conditioner outdoor unit 11 is in the defrosting mode, the first air conditioner outdoor unit 11 is disconnected from the air conditioner indoor unit 3 and is connected to the first heat exchange channel; the second air conditioner outdoor unit 12 is in the heating mode, and the second air conditioner outdoor unit 12 is connected to both the air conditioner indoor unit 3 and the second heat exchange channel; or, the first air conditioner outdoor unit 11 is in the heating mode, the first air conditioner outdoor unit 11 is connected to both the air conditioner indoor unit 3 and the first heat exchange channel; the second air conditioner outdoor unit 12 is in the defrosting mode, and the second air conditioner outdoor unit 12 is disconnected from the air conditioner indoor unit 3 and is connected to the second heat exchange channel.

[0047] During specific implementation, a control device is used to control the on-off relationship between the outdoor unit of the air conditioner and the indoor unit of the air conditioner, as well as between the outdoor unit of the air conditioner and the evaporation component, so as to achieve that in the air-conditioning system, while a part of the outdoor units of the air conditioner supply heat to the indoor unit of the air conditioner, heat is provided to a heat exchange channel of the evaporation component to evaporate the refrigerant of another defrosting flow path, enabling another part of the outdoor units of the air conditioner to achieve the effect of self-circulating defrosting by using the control device.

[0048] Specifically, the first heat exchange channel and the second heat exchange channel adopt countercurrent flow, and the heat exchange effect is better. Of course, the first heat exchange channel and the second heat exchange channel can also adopt concurrent flow, and the heat exchange effect is worse than that of countercurrent flow, such as Figure 17 .

[0049] In this embodiment, the outdoor unit 1 of the air conditioner includes a connecting pipeline, and the outdoor unit 1 of the air conditioner is connected to the indoor unit 3 of the air conditioner through the connecting pipeline; the control device includes: a defrosting pipeline, including a first defrosting pipeline and a second defrosting pipeline, both the first defrosting pipeline and the second defrosting pipeline are provided in a switchable manner, the first heat exchange channel is connected to the connecting pipeline of the first outdoor unit 11 of the air conditioner through the first defrosting pipeline, and the second heat exchange channel is connected to the connecting pipeline of the second outdoor unit 12 of the air conditioner through the second defrosting pipeline; a control valve group, and a control valve group is provided on each connecting pipeline to control the on-off of the connecting pipeline; the control valve group is located on the side of the connection point between the defrosting pipeline and the connecting pipeline close to the indoor unit 3 of the air conditioner.

[0050] During specific implementation, through the setting of the first defrosting pipeline and the second defrosting pipeline, the on-off between the first outdoor unit 11 of the air conditioner and the first heat exchange channel, and the on-off between the second outdoor unit 12 of the air conditioner and the second heat exchange channel are respectively realized; and through the setting of the control valve group, the on-off between each outdoor unit 1 of the air conditioner and the indoor unit 3 of the air conditioner is realized.

[0051] In this embodiment, the connecting pipeline includes: a first gas pipe 111, and the first gas pipes 111 of at least two outdoor units 1 of the air conditioner are all connected to the second gas pipe 301 of the indoor unit 3 of the air conditioner; a first liquid pipe 112, and the first liquid pipes 112 of at least two outdoor units 1 of the air conditioner are all connected to the second liquid pipe 302 of the indoor unit 3 of the air conditioner; the first defrosting pipeline includes a first connecting pipe assembly 21 and a second connecting pipe assembly 22, and the first port 204 of the first heat exchange channel is connected to the first liquid pipes 112 of each first outdoor unit 11 through the first connecting pipe assembly 21; the second port 205 of the first heat exchange channel is connected to the first gas pipes 111 of each first outdoor unit 11 through the second connecting pipe assembly 22; the first connecting pipe assembly 21 is provided in a switchable manner.

[0052] In specific implementation, the connection between each air conditioner outdoor unit and the air conditioner indoor unit can be realized through the settings of the first air pipe 111 and the first liquid pipe 112. Moreover, the first connecting pipe assembly 21 and the second connecting pipe assembly 22 of the first defrosting pipeline enable the first liquid pipe 112 and the first air pipe 111 of the first air conditioner outdoor unit 11 to be connected through the first heat exchange channel.

[0053] In this embodiment, the control device further includes: a first electronic expansion valve 202, which is arranged on the first connecting pipe assembly 21 to control the on-off of the first connecting pipe assembly 21. Such a setting realizes the on-off between the first air conditioner outdoor unit 11 and the evaporation component. Among them, the first electronic expansion valve 202 can adjust the flow rate according to the heat exchange requirement, and there is no flow rate when the valve is closed.

[0054] In this embodiment, the second defrosting pipeline includes a third connecting pipe assembly 23 and a fourth connecting pipe assembly 24. The third port 206 of the second heat exchange channel is connected to the first air pipe 111 of each second air conditioner outdoor unit 12 through the third connecting pipe assembly 23; the fourth port 207 of the second heat exchange channel is connected to the first liquid pipe 112 of each second air conditioner outdoor unit 12 through the fourth connecting pipe assembly 24; the fourth connecting pipe assembly 24 is arranged to be capable of being turned on and off.

[0055] In specific implementation, the third connecting pipe assembly 23 and the fourth connecting pipe assembly 24 of the second defrosting pipeline enable the first liquid pipe 112 and the first air pipe 111 of the second air conditioner outdoor unit 12 to be connected through the second heat exchange channel.

[0056] In this embodiment, the control device further includes: a second electronic expansion valve 203, which is arranged on the fourth connecting pipe assembly 24 to control the on-off of the fourth connecting pipe assembly 24. Such a setting realizes the on-off between the second air conditioner outdoor unit 12 and the evaporation component. Among them, the second electronic expansion valve 203 can adjust the flow rate according to the heat exchange requirement, and there is no flow rate when the valve is closed.

[0057] In this embodiment, the control valve group includes a first valve 211 and a second valve 212. The first valve 211 is arranged on the first air pipe 111 and is located on the side closer to the air conditioner indoor unit 3 at the connection point between the defrosting pipeline and the connecting pipeline. The second valve 212 is arranged on the first liquid pipe 112 and is located on the side closer to the air conditioner indoor unit 3 at the connection point between the defrosting pipeline and the connecting pipeline. Such a setting facilitates the control of the on-off of the first air pipe 111 and the first liquid pipe 112.

[0058] In specific implementation, the first valve 211 and the second valve 212 can be switched on and off bidirectionally.

[0059] In this embodiment, the air conditioning system includes a main air pipe 401 and a main liquid pipe 402. The connecting pipelines include: a first air pipe 111. The first air pipes 111 of at least two air conditioning outdoor units 1 are all connected to the second air pipe 301 of the air conditioning indoor unit 3 through the main air pipe 401; a first liquid pipe 112. The first liquid pipes 112 of at least two air conditioning outdoor units 1 are all connected to the second liquid pipe 302 of the air conditioning indoor unit 3 through the main liquid pipe 402. Such a setting realizes the connection of multiple air conditioning outdoor units to the air conditioning indoor unit.

[0060] In this embodiment, the number of the air conditioning outdoor units 1 is 2 or 3 or 4; when the number of the air conditioning outdoor units 1 is 2, N = 1, M = 1; when the number of the air conditioning outdoor units 1 is 3, N = 1, M = 2; or, N = 2, M = 1; when the number of the air conditioning outdoor units 1 is 4, N = 1, M = 3; or, N = 2, M = 2; or, N = 3, M = 1.

[0061] During specific implementation, the closer the total rated cooling capacities of the first air conditioning outdoor unit 11 and the second air conditioning outdoor unit 12 are, the better the defrosting effect and the continuous heating effect of the air conditioning system are. The numbers of N and M can be selected according to the specific engineering requirements.

[0062] During specific implementation, the on-off relationships between the liquid pipes and the air pipes of the air conditioning outdoor unit and the air conditioning indoor unit, and between the air conditioning outdoor unit and the evaporation component are controlled by the first valve 211, the second valve 212, the first electronic expansion valve 202, and the second electronic expansion valve 203 of the control device, so as to realize that in the air conditioning system, while a part of the air conditioning outdoor units supply heat to the air conditioning indoor unit, heat is provided to a heat exchange channel of the evaporation component to evaporate the refrigerant of another defrosting flow path, so that another part of the air conditioning outdoor units realize the effect of self-circulation defrosting by using the control device.

[0063] Specifically, for the air conditioning system with two air conditioning outdoor units, that is, the first embodiment:

[0064] The first port 204 is connected to the first liquid pipe 112 of the first air conditioning outdoor unit 11 at point e through the first electronic expansion valve 202, and the second port 205 is connected to the first air pipe 111 of the first air conditioning outdoor unit 11 at point f. The fourth port 207 is connected to the first liquid pipe 112 of the second air conditioning outdoor unit 12 at point g through the second electronic expansion valve 203, and the third port 206 is connected to the first air pipe 111 of the second air conditioning outdoor unit 12 at point h. A first valve 211 is provided between point f and the main air pipe 401, and a second valve 212 is provided between point e and the main liquid pipe 402. A first valve 211 is provided between point h and the main air pipe 401, and a second valve 212 is provided between point g and the main liquid pipe 402.

[0065] During the operation of the refrigeration mode, the schematic diagram of the system flow path is shown in Figure 3, the first electronic expansion valve 202 and the second electronic expansion valve 203 are closed, and the first valves 211 and the second valves 212 corresponding to the two air conditioner outdoor units 1 are both open. The medium-temperature and medium-pressure refrigerant after heat exchange in the condensers of the two air conditioner outdoor units 1 flows out from each first liquid pipe 112, respectively flows through each second valve 212, converges at the main liquid pipe 402, and enters the indoor-side evaporator for heat exchange through the second liquid pipe 302, evaporates into a low-temperature and low-pressure refrigerant, flows into the main gas pipe from the second gas pipe 301 of the air conditioner indoor unit 3, respectively flows through each first valve 211, returns to the suction side of each air conditioner outdoor unit through each first gas pipe 111, and starts the next cycle.

[0066] When operating in the heating mode, see the schematic diagram of the system flow path in Figure 4 . The first electronic expansion valve 202 and the second electronic expansion valve 203 are closed, and the first valves 211 and the second valves 212 corresponding to the two air conditioner outdoor units 1 are both open. The high-temperature and high-pressure refrigerant coming out of the high-pressure side of the outdoor unit flows through each first gas pipe 111, respectively flows through each first valve 211, converges at the main gas pipe 401, enters the indoor side for heat exchange through the second gas pipe 301, condenses into a medium-temperature and medium-pressure refrigerant, flows into the main liquid pipe 402 from the second liquid pipe 302, respectively flows through each second valve 212, returns to the heat exchanger of each air conditioner outdoor unit 1 through each first liquid pipe 112 for further heat exchange, and returns to the suction side to start the next cycle.

[0067] When the first air conditioner outdoor unit 11 is in the defrosting mode and the second air conditioner outdoor unit 12 is in the heating mode, see the system flow path diagram in the appendix Figure 1。The first valves 211 and second valves 212 corresponding to the first air conditioner outdoor unit 11 are closed, and the first valves 211 and second valves 212 corresponding to the first electronic expansion valve 202, second electronic expansion valve 203, and second air conditioner outdoor unit 12 are opened. The medium-temperature and medium-pressure refrigerant after heat exchange in the condenser of the first air conditioner outdoor unit 11 flows out from the first liquid pipe 112, enters the first electronic expansion valve 202 through point e for throttling and pressure reduction, enters from the first port 204 of the evaporation component (i.e., the defrosting device 201), and flows out from the second port 205 of the evaporation component. Inside the evaporation component, heat exchange is completed in the first heat exchange channel and the second heat exchange channel. The refrigerant in the first heat exchange channel absorbs heat and evaporates into a low-pressure state refrigerant, and returns to the first air pipe 111 of the first air conditioner outdoor unit 11 through point f, and returns to the suction side of the first air conditioner outdoor unit 11 to complete a defrosting cycle. For the second air conditioner outdoor unit 12, the high-temperature and high-pressure refrigerant coming out from its high-pressure side enters the first air pipe 111 of the second air conditioner outdoor unit 12 and is divided into two at point h. A small part of the refrigerant flows from point h into the third port 206 of the evaporation component and flows out from the fourth port 207 of the evaporation component. Inside the evaporation component, heat exchange is completed between the second heat exchange channel in the high-temperature and high-pressure state and the first heat exchange channel in the medium-temperature and medium-pressure state. The refrigerant in the second heat exchange channel condenses into a medium-temperature and medium-pressure state and returns to the first liquid pipe 112 of the second air conditioner outdoor unit 12 through point g; most of the refrigerant flows from point h into the first valve 211 corresponding to the second air conditioner outdoor unit 12 to reach the main air pipe 401, enters the indoor side for heat exchange through the second air pipe 301, condenses into a medium-temperature and medium-pressure refrigerant, flows into the main liquid pipe 402 from the second liquid pipe 302, flows through the second valve 212 corresponding to the second air conditioner outdoor unit 12, and returns to the first liquid pipe 112 of the second air conditioner outdoor unit 12 through point g. The refrigerant in the two branches is aggregated and then enters the first liquid pipe 112 of the second air conditioner outdoor unit 12, returns to the second air conditioner outdoor unit 12 for further heat exchange, and returns to the suction side to complete a heating cycle.

[0068] When the first air conditioner outdoor unit 11 operates in the heating mode and the second air conditioner outdoor unit 12 operates in the defrosting mode, the system flow path diagram is shown in Figure 2。The first valve 211 and the second valve 212 corresponding to the second air conditioner outdoor unit 12 are closed, and the first electronic expansion valve 202, the second electronic expansion valve 203, the first valve 211, and the second valve 212 corresponding to the first air conditioner outdoor unit 11 are opened. For the second air conditioner outdoor unit 12, the medium-temperature and medium-pressure refrigerant after heat exchange in the condenser flows out from the first liquid pipe 112 of the second air conditioner outdoor unit 12, enters the second electronic expansion valve 203 through point g for throttling and pressure reduction, enters from the fourth port 207 of the evaporation component, and flows out from the third port 206 of the evaporation component. Inside the evaporation component, heat exchange is completed between the second heat exchange channel and the first heat exchange channel. The refrigerant in the second heat exchange channel absorbs heat and evaporates into a low-pressure state refrigerant, and returns to the first gas pipe 111 of the second air conditioner outdoor unit 12 through point h, returning to the suction side of the second air conditioner outdoor unit 12 to complete a defrosting cycle. For the first air conditioner outdoor unit 11, the high-temperature and high-pressure refrigerant coming out from its high-pressure side enters the first gas pipe 111 of the first air conditioner outdoor unit 11 and is divided into two at point f. A small part of the refrigerant flows from point f into the second port 205 of the evaporation component and flows out from the first port 204 of the evaporation component. Inside the evaporation component, heat exchange is completed between the first heat exchange channel in the high-temperature and high-pressure state and the second heat exchange channel in the medium-temperature and medium-pressure state. The refrigerant in the first heat exchange channel condenses into a medium-temperature and medium-pressure state and returns to the first liquid pipe 112 of the first air conditioner outdoor unit 11 through point e; most of the refrigerant flows from point f into the first valve 211 corresponding to the first air conditioner outdoor unit 11 to reach the main gas pipe 401, enters the indoor side for heat exchange through the second gas pipe 301, condenses into a medium-temperature and medium-pressure refrigerant, flows into the main liquid pipe 402 from the second liquid pipe 302, flows through the second valve 212 corresponding to the first air conditioner outdoor unit 11, and returns to the first liquid pipe 112 of the first air conditioner outdoor unit 11 through point e. The refrigerants from the two branches are aggregated and then enter the first liquid pipe 112 of the first air conditioner outdoor unit 11, return to the outdoor unit for further heat exchange, and return to the suction side to complete a heating cycle. Among them, the valve actions of the above four operating modes are summarized in Table 1.

[0069] Table 1

[0070]

[0071] It can be seen that for an air conditioning system with two air conditioner outdoor units, the defrosting operation of the two air conditioner outdoor units can be realized only by setting the defrosting device 2, reducing the product manufacturing cost and the installation space requirements.

[0072] Specifically, for an air conditioning system with three air conditioner outdoor units, that is, the second embodiment:

[0073] The additional outdoor air conditioner of the air conditioning system with three outdoor air conditioners compared to the one with two outdoor air conditioners can be set to be connected to the side of the first port 204 and the second port 205 or the side of the third port 206 and the fourth port 207. The effects are the same, and only the pipeline connection methods are different. Here, an example is given with the third outdoor air conditioner set to be connected to the side of the third port 206 and the fourth port 207.

[0074] Based on the known structure of the air conditioning system with two outdoor air conditioners, the two second outdoor air conditioners 12 are on the same side. After the fourth port 207 passes through the second electronic expansion valve 203, the fourth connecting pipe assembly 24 is divided into two parts, which are respectively connected to the first liquid pipes 112 of the two second outdoor air conditioners 12 at points g and i; the third connecting pipe assembly 23 is divided into two parts, which are respectively connected to the first gas pipes 111 of the two second outdoor air conditioners 12 at points h and j.

[0075] When operating in the cooling mode, the schematic diagram of the system flow path is shown in Figure 5 , the first electronic expansion valve 202 and the second electronic expansion valve 203 are closed, and the first valves 211 and the second valves 212 corresponding to the three outdoor air conditioners 1 are all opened. The medium-temperature and medium-pressure refrigerant flows out from the first liquid pipes 112 of each outdoor air conditioner 1, passes through the second valves 212 of each outdoor air conditioner 1 respectively, converges at the total liquid pipe 402, enters the indoor unit for heat exchange through the second liquid pipe 302, evaporates into a low-temperature and low-pressure state, flows out from the second gas pipe 301, passes through the total gas pipe 401, passes through the first valves 211 of each outdoor air conditioner 1 respectively, returns to the first gas pipes 111 of each outdoor air conditioner 1, returns to the suction side of each outdoor air conditioner 1, and starts the next cooling cycle.

[0076] When operating in the heating mode, the schematic diagram of the system flow path is shown in Figure 6 , the first electronic expansion valve 202 and the second electronic expansion valve 203 are closed, and the first valves 211 and the second valves 212 corresponding to the three outdoor air conditioners 1 are all opened. The high-temperature and high-pressure refrigerant flows out from the first gas pipes 111 of each outdoor air conditioner 1, passes through the first valves 211 of each outdoor air conditioner 1 respectively, converges at the total gas pipe 401, enters the air conditioning indoor unit 3 for heat exchange through the second gas pipe 301, condenses into a medium-temperature and medium-pressure state, flows out from the second liquid pipe 302, passes through the total liquid pipe 402, passes through the second valves 212 of each outdoor air conditioner 1 respectively, returns to the first liquid pipes 112 of each outdoor air conditioner 1, returns to the outdoor side for further heat exchange, and returns to the suction side, and starts the next heating cycle.

[0077] In the defrosting mode of the first outdoor air conditioner 11 and the heating mode of the two second outdoor air conditioners 12, the schematic diagram of the system flow path is shown in Figure 7, the first valve 211 and the second valve 212 corresponding to the first air conditioner outdoor unit 11 are closed, and the first electronic expansion valve 202, the second electronic expansion valve 203, and the first valves 211 and the second valves 212 corresponding to the two second air conditioner outdoor units 12 are all opened. The medium-temperature and medium-pressure refrigerant after heat exchange in the condenser of the first air conditioner outdoor unit 11 flows out from the first liquid pipe 112 of the first air conditioner outdoor unit 11, enters the first electronic expansion valve 202 through point e for throttling and pressure reduction, enters from the first port 204 of the evaporation component and flows out from the second port 205 of the evaporation component. Inside the evaporation component, heat exchange is completed in the first heat exchange channel and the second heat exchange channel. The refrigerant in the first heat exchange channel absorbs heat and evaporates into a low-pressure state refrigerant, and returns to the first gas pipe 111 of the first air conditioner outdoor unit 11 through point f, and returns to the suction side of the first air conditioner outdoor unit 11 to complete a defrosting cycle. The high-temperature and high-pressure refrigerant coming out from the high-pressure sides of the two second air conditioner outdoor units 12 enters the first gas pipes 111 of the respective two second air conditioner outdoor units 12, and is divided into two parts at points h and j respectively. A small part of the refrigerant flows into the third port 206 of the evaporation component from points h and j and flows out from the fourth port 207 of the evaporation component. Inside the evaporation component, heat exchange is completed between the second heat exchange channel in the high-temperature and high-pressure state and the first heat exchange channel in the medium-temperature and medium-pressure state. The refrigerant in the second heat exchange channel condenses into a medium-temperature and medium-pressure state and returns to the first liquid pipes 112 of the respective second air conditioner outdoor units 12 through points g and i respectively; most of the refrigerant flows into the first valves 211 of the respective second air conditioner outdoor units 12 from points h and j to reach the main gas pipe 401, enters the indoor side for heat exchange through the second gas pipe 301, condenses into a medium-temperature and medium-pressure refrigerant, flows into the main liquid pipe 402 from the second liquid pipe 302, flows through the second valves 212 of the respective second air conditioner outdoor units 12 respectively, returns to the first liquid pipes 112 of the two second air conditioner outdoor units 12 through points g and i, then returns to the two second air conditioner outdoor units 12 for further heat exchange, and returns to the suction side to complete a heating cycle.

[0078] When the first air conditioner outdoor unit 11 is in the heating mode and the two second air conditioner outdoor units 12 are operating in the defrosting mode, the schematic diagram of the system flow path is shown in Figure 8, the first valves 211 and the second valves 212 corresponding to the two second air conditioner outdoor units 12 are both closed, and the first electronic expansion valve 202, the second electronic expansion valve 203, the first valves 211 and the second valves 212 corresponding to the first air conditioner outdoor unit 11 are opened. The medium-temperature and medium-pressure refrigerant after heat exchange through the condenser in the two second air conditioner outdoor units 12 flows out from the first liquid pipes 112 of the two second air conditioner outdoor units 12, enters the second electronic expansion valve 203 through points g and i for throttling and pressure reduction, enters from the fourth port 207 of the evaporation component and flows out from the third port 206 of the evaporation component. Inside the evaporation component, the second heat exchange channel and the first heat exchange channel complete heat exchange. The refrigerant in the second heat exchange channel absorbs heat and evaporates into a low-pressure state refrigerant, and returns to the first gas pipes 111 of the two second air conditioner outdoor units 12 through points h and j, and returns to the suction side of the two second air conditioner outdoor units 12 to complete a defrosting cycle. The high-temperature and high-pressure refrigerant coming out from the high-pressure side of the first air conditioner outdoor unit 11 enters the first gas pipe 111 of the first air conditioner outdoor unit 11 and is divided into two at point f. A small part of the refrigerant flows from point f into the second port 205 of the evaporation component and flows out from the first port 204 of the evaporation component. Inside the evaporation component, the first heat exchange channel in the high-temperature and high-pressure state and the second heat exchange channel in the medium-temperature and medium-pressure state complete heat exchange. The refrigerant in the first heat exchange channel condenses into a medium-temperature and medium-pressure state and returns to the first liquid pipe 112 of the first air conditioner outdoor unit 11 through point e; most of the refrigerant flows from point f into the first valve 211 corresponding to the first air conditioner outdoor unit 11 to reach the main gas pipe 401, enters the indoor side for heat exchange through the second gas pipe 301, condenses into a medium-temperature and medium-pressure refrigerant, flows into the main liquid pipe 402 from the second liquid pipe 302, flows through the second valve 212 corresponding to the first air conditioner outdoor unit 11, and returns to the first liquid pipe 112 of the first air conditioner outdoor unit 11 through point e. The refrigerant in the two branches is aggregated and then enters the first liquid pipe 112 of the first air conditioner outdoor unit 11, returns to the first air conditioner outdoor unit 11 for further heat exchange, and returns to the suction side to complete a heating cycle.

[0079] Among them, the valve body actions of the above four operating modes are summarized in Table 2.

[0080] Table 2

[0081]

[0082] It can be seen that for an air conditioner system with three air conditioner outdoor units, the defrosting operation of the three air conditioner outdoor units can be realized only by setting the defrosting device 2, reducing the product manufacturing cost and the installation space requirement.

[0083] Specifically, for an air conditioner system with four air conditioner outdoor units 1:

[0084] The connection between the four air conditioner outdoor units 1 and the defrosting device can have various forms. For example, one air conditioner outdoor unit 1 can be connected to the first port 204 and the second port 205 side, and three air conditioner outdoor units 1 can be connected to the third port 206 and the fourth port 207 side; or two air conditioner outdoor units 1 can be connected to the first port 204 and the second port 205 side, and two air conditioner outdoor units 1 can be connected to the third port 206 and the fourth port 207 side; or three air conditioner outdoor units 1 can be connected to the first port 204 and the second port 205 side, and one air conditioner outdoor unit 1 can be connected to the third port 206 and the fourth port 207 side. The closer the total rated cooling capacity of the outdoor units on the first port 204 and the second port 205 side is to the total rated cooling capacity of the outdoor units on the third port 206 and the fourth port 207 side, the better the defrosting effect and the continuous heating effect of the air conditioning system. The connection method can be selected according to the specific engineering requirements.

[0085] Here are two forms listed: an air conditioning system with two air conditioner outdoor units 1 connected to the first port 204 and the second port 205 side, and two air conditioner outdoor units 1 connected to the third port 206 and the fourth port 207 side; an air conditioning system with one air conditioner outdoor unit 1 connected to the first port 204 and the second port 205 side, and three air conditioner outdoor units 1 connected to the third port 206 and the fourth port 207 side.

[0086] The first form, that is, the third embodiment: an air conditioning system with two air conditioner outdoor units 1 connected to the first port 204 and the second port 205 side, and two air conditioner outdoor units 1 connected to the third port 206 and the fourth port 207 side, that is, M = N = 2. See the schematic diagram of the refrigerant flow path of the system in Figures 9 to 12 .

[0087] Compared with the known outdoor unit air conditioning system with three air conditioner outdoor units, one air conditioner outdoor unit 1 is added to the first port 204 and the second port 205 side. After passing through the first electronic expansion valve 202 from the first port 204 of the evaporation component, the first connecting pipe assembly 21 is divided into two. One path is connected to the first liquid pipe 112 of a first air conditioner outdoor unit 11 at point e, and the other path is connected to the first liquid pipe 112 of another first air conditioner outdoor unit 11 at point k; the second connecting pipe assembly 22 is divided into two. One path is connected to the first gas pipe 111 of a first air conditioner outdoor unit 11 at point f, and the other path is connected to the first gas pipe 111 of another first air conditioner outdoor unit 11 at point m. The third port 206 and the fourth port 207 side are the same as the air conditioning system with three air conditioner outdoor units.

[0088] Among them, the valve body actions of the four operating modes are summarized in Table 3.

[0089] Table 3

[0090]

[0091] The second form, i.e., the fourth embodiment: An air-conditioning outdoor unit 1 is connected to the first port 204 and the second port 205 side, and three air-conditioning outdoor units 1 are connected to the third port 206 and the fourth port 207 side. That is, M = 1 and N = 3. The schematic diagram of the refrigerant flow path of the system can be seen in Figures 13 - 16 .

[0092] Compared with the known outdoor unit air-conditioning system with three air-conditioning outdoor units, an air-conditioning outdoor unit 1 is added to the third port 206 and the fourth port 207 side. After the fourth port 207 passes through the second electronic expansion valve 203, the fourth connecting pipe assembly 24 is divided into three parts, which are respectively connected to the first liquid pipes 112 of the three second air-conditioning outdoor units 12 at points g, i, and k; the third connecting pipe assembly 23 is divided into three parts, which are respectively connected to the first gas pipes 111 of the three second air-conditioning outdoor units 12 at points h, j, and m.

[0093] Among them, the valve body actions of the four operating modes are summarized in Table 4.

[0094] Table 4

[0095]

[0096] It can be seen that for an air-conditioning system with four air-conditioning outdoor units, the defrosting operation of the four air-conditioning outdoor units can be realized only by setting the defrosting device 2, reducing the product manufacturing cost and the installation space requirements.

[0097] In other embodiments, when the number of air-conditioning outdoor units is increased under feasible conditions, this technical solution is also applicable.

[0098] The present invention solves the technical problem: For the technical effect of realizing that the indoor unit can supply heat to the indoor side synchronously during the defrosting process, in the existing technical solutions, each outdoor unit must be equipped with a defrosting control device, resulting in high manufacturing cost and high installation space requirements.

[0099] The beneficial effects of the present invention: In the air-conditioning system, while a part of the air-conditioning outdoor units supply heat to the air-conditioning indoor unit, heat is provided to a heat exchange channel of the evaporation component to realize the evaporation of the refrigerant in another defrosting flow path, so that another part of the air-conditioning outdoor units can realize the effect of self-circulation defrosting by using the control device. The air-conditioning system can achieve the same technical effect by only equipping one defrosting control device for multiple air-conditioning outdoor units, reducing the manufacturing cost and the requirements for the installation space.

[0100] From the above description, it can be seen that the above embodiments of the present invention achieve the following technical effects:

[0101] The air conditioning system of the present invention includes at least two outdoor air conditioners 1 and an indoor air conditioner 3. Each outdoor air conditioner 1 is connected to the indoor air conditioner 3. The air conditioning system further includes a defrosting device 2, which includes a control device and a defrosting device 201. The defrosting device 201 is connected to each outdoor air conditioner 1 through the control device to defrost each outdoor air conditioner 1. It can be seen that the air conditioning system can realize the defrosting operation of multiple outdoor air conditioners 1 only by setting the defrosting device 2, reducing the product manufacturing cost and facilitating installation, and solving the problem of high manufacturing cost of the air conditioning system.

[0102] It should be noted that the terms "first", "second", etc. in the description, claims and above-mentioned drawings of this application are used to distinguish similar objects and do not necessarily describe a specific order or sequence. It should be understood that such used data can be interchanged under appropriate circumstances so that the embodiments of this application described here can be implemented in an order other than those illustrated or described here. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device that includes a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0103] For the sake of convenience of description, spatial relative terms such as "above...", "over...", "on the upper surface of...", "above" etc. can be used here to describe the spatial position relationship between a device or feature and other devices or features as shown in the figure. It should be understood that the spatial relative terms are intended to include different orientations in use or operation in addition to the orientation of the device described in the figure. For example, if the device in the figure is inverted, the device described as "above other devices or structures" or "over other devices or structures" will be positioned as "below other devices or structures" or "under other devices or structures" afterwards. Thus, the exemplary term "above..." can include both the orientations of "above..." and "below...". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the corresponding explanations are made for the spatial relative descriptions used here.

[0104] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. An air conditioning system, comprising at least two outdoor air conditioners (1) and an indoor air conditioner (3), each of the outdoor air conditioners (1) being connected to the indoor air conditioner (3), characterized in that, The air conditioning system further includes: A defrosting device (2), including a control device and a defrosting device (201), wherein the defrosting device (201) is connected to each of the air conditioner outdoor units (1) through the control device to perform defrosting operations on each of the air conditioner outdoor units (1).

2. The air conditioning system according to claim 1, characterized in that, The defrosting device (201) is an evaporation component, and the evaporation component includes a first heat exchange channel and a second heat exchange channel for heat exchange; at least two of the air conditioner outdoor units (1) include N first air conditioner outdoor units (11) and M second air conditioner outdoor units (12); wherein, 1 ≤ N < the total number of the air conditioner outdoor units (1); 1 ≤ M < the total number of the air conditioner outdoor units (1); The control device is used to control the on-off between the first air conditioner outdoor unit (11) and the air conditioner indoor unit (3), the on-off between the second air conditioner outdoor unit (12) and the air conditioner indoor unit (3), the on-off between the first air conditioner outdoor unit (11) and the first heat exchange channel, and the on-off between the second air conditioner outdoor unit (12) and the second heat exchange channel; the air conditioning system has a defrosting state, and when the air conditioning system is in the defrosting state, The first air conditioner outdoor unit (11) is in the defrosting mode, the first air conditioner outdoor unit (11) is disconnected from the air conditioner indoor unit (3) and is connected to the first heat exchange channel; the second air conditioner outdoor unit (12) is in the heating mode, and the second air conditioner outdoor unit (12) is connected to both the air conditioner indoor unit (3) and the second heat exchange channel; or The first air conditioner outdoor unit (11) is in the heating mode, the first air conditioner outdoor unit (11) is connected to both the air conditioner indoor unit (3) and the first heat exchange channel; the second air conditioner outdoor unit (12) is in the defrosting mode, and the second air conditioner outdoor unit (12) is disconnected from the air conditioner indoor unit (3) and is connected to the second heat exchange channel.

3. The air conditioning system according to claim 2, wherein The air conditioner outdoor unit (1) includes a connecting pipeline, and the air conditioner outdoor unit (1) is connected to the air conditioner indoor unit (3) through the connecting pipeline; the control device includes: A defrosting pipeline, including a first defrosting pipeline and a second defrosting pipeline, both the first defrosting pipeline and the second defrosting pipeline are provided in a switchable manner, the first heat exchange channel is connected to the connecting pipeline of the first air conditioner outdoor unit (11) through the first defrosting pipeline, and the second heat exchange channel is connected to the connecting pipeline of the second air conditioner outdoor unit (12) through the second defrosting pipeline; A control valve group, and the control valve group is provided on each of the connecting pipelines to control the on-off of the connecting pipeline; the control valve group is located on the side of the connection point between the defrosting pipeline and the connecting pipeline close to the air conditioner indoor unit (3).

4. The air conditioning system according to claim 3, characterized in that, The connecting pipeline includes: A first air pipe (111), and the first air pipes (111) of at least two of the air conditioner outdoor units (1) are all connected to the second air pipe (301) of the air conditioner indoor unit (3); The first liquid pipe (112), the first liquid pipes (112) of at least two of the air conditioner outdoor units (1) are all connected to the second liquid pipe (302) of the air conditioner indoor unit (3); The first defrosting pipeline includes a first connecting pipe assembly (21) and a second connecting pipe assembly (22). The first port (204) of the first heat exchange channel is connected to the first liquid pipes (112) of each of the first air conditioner outdoor units (11) through the first connecting pipe assembly (21); the second port (205) of the first heat exchange channel is connected to the first gas pipes (iii) of each of the first air conditioner outdoor units (11) through the second connecting pipe assembly (22); the first connecting pipe assembly (21) is provided in a switchable manner.

5. The air conditioning system according to claim 4, characterized in that, The control device further includes: A first electronic expansion valve (202), which is arranged on the first connecting pipe assembly (21) to control the on-off of the first connecting pipe assembly (21).

6. The air conditioning system according to claim 4, characterized in that, The second defrosting pipeline includes a third connecting pipe assembly (23) and a fourth connecting pipe assembly (24). The third port (206) of the second heat exchange channel is connected to the first gas pipes (iii) of each of the second air conditioner outdoor units (12) through the third connecting pipe assembly (23); the fourth port (207) of the second heat exchange channel is connected to the first liquid pipes (112) of each of the second air conditioner outdoor units (12) through the fourth connecting pipe assembly (24); the fourth connecting pipe assembly (24) is provided in a switchable manner.

7. The air conditioning system according to claim 6, characterized in that, The control device further includes: A second electronic expansion valve (203), which is arranged on the fourth connecting pipe assembly (24) to control the on-off of the fourth connecting pipe assembly (24).

8. The air conditioning system according to claim 3, wherein, The connecting pipeline includes: A first gas pipe (iii), the first gas pipes (iii) of at least two of the air conditioner outdoor units (1) are all connected to the second gas pipe (301) of the air conditioner indoor unit (3); A first liquid pipe (112), the first liquid pipes (112) of at least two of the air conditioner outdoor units (1) are all connected to the second liquid pipe (302) of the air conditioner indoor unit (3); The control valve group includes a first valve (211) and a second valve (212). The first valve (211) is arranged on the first gas pipe (iii) and is located on the side of the connection point between the defrosting pipeline and the connecting pipeline close to the air conditioner indoor unit (3), and the second valve (212) is arranged on the first liquid pipe (112) and is located on the side of the connection point between the defrosting pipeline and the connecting pipeline close to the air conditioner indoor unit (3).

9. The air conditioning system according to claim 3, characterized in that, The air conditioning system includes a main gas pipe (401) and a main liquid pipe (402), and the connecting pipeline includes: A first gas pipe (iii), the first gas pipes (iii) of at least two of the air conditioner outdoor units (1) are all connected to the second gas pipe (301) of the air conditioner indoor unit (3) through the main gas pipe (401); The first liquid pipe (112), and the first liquid pipes (112) of at least two of the air conditioner outdoor units (1) are all connected to the second liquid pipe (302) of the air conditioner indoor unit (3) through the main liquid pipe (402).

10. The air conditioning system according to claim 2, wherein The number of the air conditioner outdoor units (1) is two or three or four; When the number of the air conditioner outdoor units (1) is two, N = 1 and M = 1; When the number of the air conditioner outdoor units (1) is three, N = 1 and M = 2; Or, N = 2 and M = 1; When the number of the air conditioner outdoor units (1) is four, N = 1 and M = 3; Or, N = 2 and M = 2; Or, N = 3 and M = 1.

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